This appears to be on the right track, but I have no way of viewing the
other changes, and no way of viewing the changes in context, so I don't see
how I can determine whether the changes are satisfactory.
Peter F. Patel-Schneider
Bell Labs Research
Lucent Technologies
From: Dan Brickley <danbri@w3.org>
Subject: Re: pfps-12 lists are not well formed
Date: Wed, 18 Jun 2003 12:28:27 -0400
> resent copying Karsten, who also raised this issue. Karsten, could you
> respond per the request below, letting us know if this is a satisfactory
> resolution of your concern?
>
> Thanks again for your comments on our work,
>
> Dan
>
> previous discussion:
> http://lists.w3.org/Archives/Public/www-rdf-comments/2003JanMar/0422.html
>
> * Dan Brickley <danbri@w3.org> [2003-06-18 12:16-0400]
> >
> > * Peter F. Patel-Schneider <pfps@research.bell-labs.com> [2003-05-25 07:24-0400]
> > >
> > > From: Brian McBride <bwm@hplb.hpl.hp.com>
> > > Subject: pfps-12 lists are not well formed
> > > Date: Sat, 24 May 2003 13:58:39 +0100
> > >
> > > > Peter,
> > > >
> > > > Danbri and I have been discussing how to resolve your issue about the
> > > > wellformedness of lists:
> > > >
> > > > http://www.w3.org/2001/sw/RDFCore/20030123-issues/#pfps-12
> > > >
> > > > We are proposing to add the following note to the text at:
> > > >
> > > > http://www.w3.org/TR/rdf-schema/#ch_collectionvocab
> > > >
> > > > as the last paragraph.
> > > >
> > > > [[
> > > > NOTE: It is possible to construct RDF graphs that use the RDF collections
> > > > vocabulary to partially describe a list. Similarly there are graphs that
> > > > use this vocabulary in a way that is consistent with the RDF(S) formal
> > > > semantics, yet do not represent "well formed" lists.
> > > > ]]
> > > >
> > > > We considered trying to trying to provide a full prose account of the
> > > > wellformedness of lists, but are currently disinclined to attempt such an
> > > > intricate task in natural language.
> > > >
> > > > Will adding this note address your concern. If not, could you please
> > > > suggest alternative text that you would find more satisfactory.
> > > >
> > > > Brian
> > >
> > > I fail to see how this response addresses my comment.
> > >
> > > I don't see how it addresses
> > >
> > > > The RDF Schema document provides intended meanings for some of the RDFS
> > > > vocabulary that is not supported by the RDF Semantics. Vocabulary that
> > > > fits into this category includes rdfs:label and rdfs:comment.
> > > [from http://lists.w3.org/Archives/Public/www-rdf-comments/2003JanMar/0126.html]
> > >
> > > I don't see how it addresses
> > >
> > > > Consider the following three examples (slightly reformatted but otherwise
> > > > unchanged):
> > > >
> > > > rdf:type is an instance of rdf:Property that is used to state that
> > > > a resource is an instance of a class. A triple of the form:
> > > > R rdf:type C
> > > > states that C is an instance of rdfs:Class and R is an instance of C.
> > > >
> > > > rdf:first is an instance of rdf:Property that is used to indicate
> > > > the first item of a list. A triple of the form:
> > > > L rdf:first O
> > > > states that L is an instance of rdf:List and that O is the first
> > > > item of the list.
> > > >
> > > > rdfs:label is an instance of rdf:Property that is used to provide a
> > > > human-readable version of a resource's name. A triple of the form:
> > > > R rdfs:label L
> > > > states that L is a human readable label for R.
> > > >
> > > > There is essentially no difference between the way these three are worded.
> > > > However, the first (rdf:type) is a fundamental part of the semantics of
> > > > RDF. There are semantic conditions in RDF that make the description above
> > > > for rdf:type part of the very meaning of RDF. The second (rdf:first) and
> > > > third (rdfs:label), on the other hand, have a very different status. There
> > > > are no semantic conditions that force the descriptions above for these two
> > > > vocabulary elements to play the roles given for them.
> > > [from http://lists.w3.org/Archives/Public/www-rdf-comments/2003JanMar/0133.html]
> > >
> > > The point of my comments here has always been that there are parts of the
> > > RDF Schema document that go beyond what is supported by the RDF semantics.
> > > I believe that these parts of the document should be changed, and that
> > > changes to other parts of the document will not suffice to override these
> > > over-reaching parts of the document.
> > >
> > > For the case of rdf:first above, I would much prefer
> > >
> > > rdf:first is an instance of rdf:Property that can be used to build
> > > descriptions of lists and other list-like structures. A triple of
> > > the form:
> > > L rdf:first O
> > > states that there is a first-element relationship between L and O.
> > >
> > > Note: RDFS does not require that there be only one first element
> > > of a list-like structure, or even that a list-like structure have a
> > > first element.
> >
> > This looks good. At the June 6th telecon[1] we decided to run with your
> > proposed form of words, but note that your text didn't mention the
> > domain and range constraints associated with these concepts.
> >
> > A slightly amended form is:
> > [[
> > rdf:first is an instance of rdf:Property that can be used to
> > build descriptions of lists and other list-like structures.
> > A triple of the form:
> >
> > L rdf:first O
> >
> > states that there is a first-element relationship between L and O.
> > The rdfs:domain of rdf:first is rdf:List. The rdfs:range of rdf:first
> > is rdfs:Resource.
> >
> > Note: RDFS does not require that there be only one first element of
> > a list-like structure, or even that a list-like structure have a first
> > element.
> > ]]
> >
> >
> > > I note that similar changes would have to be make for at least rdf:rest and
> > > rdf:List.
> >
> > Agreed.
> >
> > The WG (per [1]) proposes to close this issue by resolving to adopt text in the
> > above form for the RDF lists vocabulary.
> >
> > Please reply to this message as to whether this response is
> > satisfactory, copying www-rdf-comments@w3.org.
> >
> > Dan
> >
> > [1] http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003Jun/0067.html